How often should a Coronary Computed Tomography (CT) Angiogram be repeated?

From the Guidelines

The frequency of repeating a coronary CT angiogram should be individualized, but generally, it should not be performed routinely without specific indications, with the most recent guidelines suggesting repeat scanning every 5 years for low-risk individuals or those with CAC = 0, and every 3 years for diabetic patients or those with CAC 101 to 400 1. When considering the repetition of a coronary CT angiogram, several factors must be taken into account, including the patient's clinical situation, risk factors, and the results of previous scans.

• For patients with known coronary artery disease (CAD), a repeat CCTA might be considered every 3-5 years if there are new or worsening symptoms, changes in risk factors, or to evaluate the progression of previously identified disease.
• For asymptomatic individuals with high-risk factors who had a previous normal or minimally abnormal scan, repeating every 5 years may be reasonable, as suggested by the ACC/AHA and CSANZ guidelines 1.
• However, for those with moderate to severe coronary artery disease identified on initial CCTA, follow-up might be recommended sooner, typically within 1-2 years, especially if medical therapy has been initiated or changed. The decision to repeat a CCTA should balance the potential benefits of detecting disease progression against the risks of radiation exposure and contrast administration, as highlighted by the 2010 appropriate use criteria for cardiac computed tomography 1. Alternative testing methods like stress tests or invasive coronary angiography might be more appropriate in certain situations, particularly for patients with known significant coronary stenosis or those who have undergone coronary interventions. Always consult with a cardiologist to determine the most appropriate timing for repeat imaging based on your specific clinical circumstances, taking into account the latest guidelines and recommendations from reputable organizations such as the ACC/AHA and CSANZ 1.

From the Research

Frequency of Coronary CT Angiogram Repeats

The frequency of repeating a coronary CT angiogram depends on various factors, including the patient's risk profile, symptoms, and the results of the initial scan.

• According to 2, repeat coronary computed tomographic angiography (CCTA) may not be necessary for patients with a prior scan excluding significant stenosis, especially if the time difference between the studies is less than 3 years and the patient does not have diabetes mellitus or 26% to 50% stenosis on the initial CCTA.
• The study 2 found that when these factors were all absent, the probability of significant stenosis was 4.5%, and when coronary arteries were completely normal at the initial scan, the prevalence of significant stenosis was only 1.8%.
• Another study 3 found that truly normal coronary arteries do not progress to significant disease within a time frame of 4 years, suggesting that repeat coronary angiography within that period is probably not indicated.
• However, 4 suggests that the threshold for repeat angiography should be higher and better reserved for troponin positive cases, and that patients should be handled according to their risk profile.

Patient Risk Profile and Symptoms

The decision to repeat a coronary CT angiogram should also take into account the patient's risk profile and symptoms.

• 4 found that male gender, BMI above 30, hypertension, diabetes, and smoking were significantly higher in the interventional group, and that regression analysis showed both paroxysmal atrial fibrillation and hyperlipidemia were significantly associated with repeat CAG.
• 2 identified diabetes mellitus as a predictor of significant stenosis, and found that nondiabetic patients with a prior CCTA <3 years showing no or ≤25% stenosis had a <5% prevalence of significant stenosis.

Imaging Techniques and Guidelines

Recent advances in imaging techniques, such as cardiac CT, have improved the diagnosis of coronary artery disease.

• 5 reviews established and emerging techniques of cardiac computed tomography (CT) and their clinical applications, and provides practical recommendations on when and how to perform cardiac CT.
• 6 discusses the latest National Institute for Health and Care Excellence and European College of Cardiology guidelines, which emphasize the importance of using imaging techniques first to inform diagnosis.